Y axis screw is jumping. Maybe about 0.002-0.003". Worse in one direction, and "appears" to be more prevalent in one location. But may be along the length of the travel. It jumps about every 1/2". Perhaps each screw revolution?

Is this likely:
1. a bad spot on the screw, or
2, a bad ball in the nut circuit, or the nut itself, or
3. a bad spot in the thrust bearing?


clay